The Environmental Protection Agency waives its fees for big "green" groups 92 percent of the time while it waives fees for major conservative groups only seven percent of the time, the Competitive Enterprise Institute said Tuesday.

EPA records provided to the CEI in response to a Freedom of Information Act lawsuit "illustrate a pattern of making it far more difficult for limited-government groups – in particular those who argue for more freedom and less EPA – to access public records," the CEI reported.

"Such groups are precisely those Congress and courts made clear FOIA was intended to protect from fees being used as a hurdle to obtaining information, without prejudice as to their perspective," CEI said. The EPA, it argues, gave favor to "the same green groups it’s been shown to be collaborating with on its agenda."

The EPA routinely waives fees when the information they are providing is requested by media outlets or by watchdog groups. But CEI said it found its own requests denied most of the time.

CEI Senior Fellow Christopher Horner reviewed letters either granting or denying fee waivers from January 2012 until spring 2013. In that time, Horner reported that "green" groups, such as the National Resources Defense Council, Sierra Club, Public Employees for Environmental Responsibility and EarthJustice, obtained waivers in 75 out of 82 cases.

In the same period, Horner's own requests for waivers were denied 14 out of 15 times. Every denial that Horner appealed was overturned. The report did not say whether he appealed all denials.

“That these denials are ritually overturned on appeal, not after I presented any new evidence or made any new point, but simply restated what was a detailed and heavily sourced legal document to begin with, reaffirms the illegitimacy of these hurdles EPA places in the way of those who cause it problems.” Horner said. “EPA’s practice is to take care of its friends and impose ridiculous obstacles to deny problematic parties’ requests for information.”